JP2000251299A - Optical disk device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a writing error from occurring due to the reduction and position deviation of a recording mark. SOLUTION: An optical disk device uses a semiconductor laser as a light source and has an optical pick-up mechanism for forming a spot beam for an optical pick-up on an optical disk surface due to an optical system. In this case, in the said semiconductor laser, the width of a current injection part corresponding to a resonator part where the width of the undulation of the standing wave being generated in a resonator to prevent kinks from occurring is maximized is narrower than the other parts. The length of a narrow part 40 where the width of the current injection part becomes narrow is equal to that of a part where the current injection part does not become narrow. The narrow part 40 where the width of the current injection part becomes narrow is set to width where the primary mode of an emission laser beam can be cut off. The semiconductor composes a high-output semiconductor laser in ridge structure for writing onto the optical disk surface. The width of the resonator is constant.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a DVD (Digital Vi
deo Disk), AS-MO (Advanced Storage-Magneto O
ptical), high-speed recording CD-R (Compact Disc-Recordabl)
The present invention relates to an optical disk device such as e), and particularly to a technology effective when applied to an optical disk device having a writing function.

[0002]

2. Description of the Related Art DVD-Rs are one of optical disk devices.
AM devices are known. In the DVD-RAM device, a recording method based on a phase change is used, and writing is performed by changing a recording thin film from a crystal to an amorphous by heat of laser high resistance to form a recording mark having a changed reflectance.

[0003] In the conventional CD, a mark position (position) recording method in which a signal is made to correspond to the center of a recording mark is used.
A mark edge method in which a signal is put on both ends of a recording mark is adopted. For this reason, it is necessary to write a mark on the recording track of the disk without shifting the edge position. Particularly, in the case of a long recording mark, laser light is continuously irradiated, and the recording mark is deformed into a tear shape due to accumulation of heat, and the position of the edge is shifted. To prevent this displacement, a multi-pulse method of writing one recording mark with a plurality of pulses is used.

[0004] These technologies are described in “Optics”, Vol. 26, No. 1, P9-P published by the Optical Society of Japan, Japan Society of Applied Physics.
15 “High-density recording technology for phase-change optical disks”. Also, "Applied Physics" Vol. 67, No. 9 (1998), pp. 1035 to 1040, published by the Japan Society of Applied Physics, describes semiconductor lasers for optical disks. As for the optical pickup for DVD, see “OpplusE” published by Shin-Technologies Communications, Inc., No. 199, pp. 86-92.
It is described in. This document describes three types of DVD / CD compatible reproduction optical pickups: (1) lens switching method, (2) focus lens method, and (3) liquid crystal shutter method.
The method is described.

[0005]

As a conventional method of forming a recording mark, a method as shown in FIG. 5 is known. FIG.
FIG. 5A shows the result of the multi-pulse method, and FIG.
Is based on a mark position recording method. That is, in the optical disk device, the optical output of the laser beam in a state where reading (reproduction) and writing are not performed is in a bias power state, and reading (reproduction) is performed with reproduction power and writing is performed with peak power. Recording track 70
Is formed of a crystalline portion, and the recording mark 71 is formed by changing the crystalline portion to an amorphous portion by writing with peak power.

In the mark position recording method shown in FIG. 5B, laser light is continuously irradiated (peak power) on a long recording mark 71a, and the recording mark is deformed into a tear shape due to accumulation of heat, so that the edge is removed. Is shifted (position shift e). In order to solve this problem, in the mark edge recording by the multi-pulse method of FIG. 5A, one recording mark 71 is written with a plurality of pulses (multi-pulses) at the peak power at the time of writing. Edges are not displaced so that they do not become molds.

When the multi-pulse method is adopted, the minimum driving pulse width is as high as several tens ns, so that the laser is driven with a constant current. Therefore, linearity of the current-light output characteristics of the laser is required. If this linearity is poor, especially if the linearity bends due to pulse width, etc., the required laser output will not reach the required peak power with a constant current drive, and the recording mark will become smaller, or the position of the recording mark will shift. And correct writing cannot be performed.

FIG. 6 is a diagram showing mark edge recording by a laser having poor current-light output linearity, and is an explanatory diagram showing a defective mark edge recording state caused by kink. In the multi-pulse method, when the kink 72 occurs when the optical output of the semiconductor laser is increased and the bias power is shifted from the bias power to the peak power, the required laser output does not reach the required peak power with constant current driving, and the recording mark 71 ( The long recording mark 71a) becomes smaller than the theoretical recording mark 75, or the position of the recording mark 71 is shifted. This shift (f) occurs on the head side, contrary to the shift (e) that occurs on the tail in the case of FIG. 5B.

It is an object of the present invention to provide an optical disk apparatus capable of preventing a writing error due to a reduction in the size of a recording mark or a positional shift. The above and other objects and novel features of the present invention will become apparent from the description of the present specification and the accompanying drawings.

[0010]

The following is a brief description of an outline of typical inventions disclosed in the present application.

(1) An optical disk apparatus having an optical pickup mechanism using a semiconductor laser as a light source and connecting a spot light for optical pickup to an optical disk surface by an optical system, wherein the semiconductor laser has a resonator for suppressing kink generation. The width of the current injection portion corresponding to the resonator portion where the swell width of the swell of the swell generated at the maximum becomes a narrower value than the other portions. The length of the narrow portion where the width of the current injection portion is narrow is equal to the length of the portion where the width of the current injection portion is not narrow. The narrow portion where the width of the current injection portion is narrow has a width that can reduce the gain of the primary mode of the emitted laser light. The semiconductor laser constitutes a high-output semiconductor laser capable of writing on the optical disk surface. The semiconductor laser is a semiconductor laser having a cavity having a ridge structure, a buried heterostructure, or the like, having an internally confined cavity. The width of the resonator is constant. The semiconductor laser is incorporated in a package consisting of a package main body and a lid having a light transmission window for transmitting laser light, and each electrode of the semiconductor laser is attached to the package main body and inside and outside the package. It is configured to be electrically connected to a plurality of external electrode terminals extending over the connection means via connection means.

According to the means (1), (a) in a semiconductor laser for writing data on an optical disk, the width of the current injection portion at which the width of the undulation of the standing wave of the undulation in the resonator is narrow is narrow. Structure (narrow structure)
Therefore, in this narrow portion, the gain of the higher-order modes including the first-order mode is reduced, the generation of the standing wave having the undulation can be suppressed, and the generation of the kink can be suppressed. Accordingly, it is possible to prevent the occurrence of a writing error such as a reduction in the size of a recording mark or a positional shift on an optical disc. (B) Since no kink occurs, even if the drive pulse width changes, the linearity of the current-light output characteristics can be prevented from deteriorating, and the fluctuation of the light output during constant current driving can be prevented. (C) An additional circuit for correcting the light output at high speed is required to reduce the writing failure with a laser having poor current-light output characteristic linearity. Since the linearity of the light output characteristics is improved, a correction circuit is not required, and simplification and downsizing of the circuit of the optical disk device can be achieved. (D) Since the yield of the linearity of the current-optical output characteristics of the semiconductor laser is improved, the cost of the semiconductor laser is reduced, and the cost of the optical disk device can be reduced.

[0013]

Embodiments of the present invention will be described below in detail with reference to the drawings. In all the drawings for describing the embodiments of the present invention, components having the same functions are denoted by the same reference numerals, and their repeated description will be omitted.

(Embodiment 1) FIGS. 1 to 4 relate to an optical disk device according to an embodiment (Embodiment 1) of the present invention. FIG. 1 shows a semiconductor laser device incorporated in an optical pickup mechanism of the optical disk device. FIG. 2 is a schematic perspective view showing an optical pickup portion, FIG. 3 is an explanatory diagram showing a mark edge recording method and a mark edge recording state using laser light, and FIG. 4 is a semiconductor laser device. It is the perspective view which notched some parts which show this.

The optical pickup mechanism of the optical disk device is
One optical system including a module in which a semiconductor laser (LD) with an oscillation wavelength of 780 nm for reading a CD and a photodetector are integrated, and one optical system for a DVD with a semiconductor laser with an oscillation wavelength of 650 nm and a detector. Optical system. Then, reproduction (reading) and writing are performed by switching the optical system corresponding to the disc.

FIG. 2 shows an optical pickup mechanism in the optical disk device of the first embodiment. Oscillation wavelength is 650nm
The laser beam 2 emitted from the semiconductor laser 1 passes through the half mirror 3 and the collimating lens 4 in order, is reflected by the wavelength selection mirror 5, is narrowed by the DVD objective lens 7 of the two-lens actuator 6, and is recorded on the recording surface of the disk 8. It is configured to be condensed. The laser beam 2 reflected by the recording surface passes through the DVD objective lens 7, is reflected by the wavelength selection mirror 5, passes through the collimating lens 4, is reflected by the half mirror 3, and detects light having a wavelength of 650 nm. The detector 9 is focused on.

On the other hand, the optical axis connecting the DVD objective lens 7 and the wavelength selection mirror 5 has an oscillation wavelength of 780 nm.
Is disposed. The laser light 16 emitted from the semiconductor laser 15 passes through the half mirror 17 and the collimating lens 18 in order, passes through the wavelength selection mirror 5, is switched, and the two-lens actuator 6 positioned on the optical axis of the wavelength selection mirror 5 is switched. Through the CD objective lens 19 of FIG. The laser light 16 reflected by the recording surface passes through the CD objective lens 19, the wavelength selection mirror 5, and the collimating lens 18 in order, and is reflected by the half mirror 17 so as to be focused on a photodetector 20 for detecting light having a wavelength of 780 nm. It has become.

Semiconductor laser 1 and semiconductor laser 1
5 is driven and controlled by a laser drive circuit 21 operated by an input signal. The light detector 9 and the light detector 2
The output signal of 0 is amplified by the preamplifier circuit 22, and the amplified signal is demodulated by the demodulator 23. Demodulator 2
APC (Auto Power Control)
l) The laser drive circuit 21 performs correction based on the output signal of the circuit 24 and controls the optical output of each semiconductor laser.

The semiconductor laser 1 serving as a light source for DVD
Are used in three forms: a bias power in an idle state at the time of driving, a reproduction power for reading with an optical output lower than the bias power, and a peak power for writing with an optical output higher than the bias power. Is done.

In the semiconductor laser 1 according to the first embodiment, the kink does not occur even in the peak power state and the current-light output linearity is improved, as shown by the mark edge recording in FIG. Even if the long recording mark 71a is formed, there is no fluctuation (decrease and delay) in the optical output, so that the long recording mark 71
The recording mark 71 including a coincides with the theoretical recording mark 75, and the writing error due to the reduction in the size of the recording mark and the displacement does not occur. Therefore, the yield of the optical pickup mechanism is improved. Further, it is easy to simplify the configuration of the drive circuit of the semiconductor laser. As a result, a reduction in the manufacturing cost of the optical disk device can be achieved.

Next, a description will be given of the semiconductor laser 1 according to the first embodiment, in which no kink is generated. The semiconductor laser 1 and the semiconductor laser 15 shown in FIG. 2 are not particularly limited, but are incorporated as a semiconductor laser device in which a semiconductor laser element is incorporated in a package.

FIG. 1 is a schematic view showing a semiconductor laser 1 according to the first embodiment, that is, a semiconductor laser element 1a. The semiconductor laser element 1a has a structure that emits a laser beam having an oscillation wavelength in the 650 nm band. The semiconductor laser device 1a has a length (depth) of 875 μm, a width of 300 μm, and a length (depth) along the extending direction of the resonator (optical waveguide).
It is made of a rectangular body having a thickness of 100 μm.

The semiconductor laser device 1a according to the first embodiment has n
A semiconductor layer is formed as a multilayer on the upper surface of a type GaAs substrate, and an internal current confinement type ridge structure (ridge type semiconductor laser) in which both sides of a ridge provided in a stripe shape are sandwiched between block layers. Although not particularly shown, a cathode electrode is provided on the lower surface side of the semiconductor laser device 1a, and an anode electrode is provided on the upper surface side.

The semiconductor laser device 1a has a thickness of 1.5 nm on the upper surface (main surface) side of an n-type GaAs substrate (semiconductor substrate) 30.
μm n-type AlGaInP cladding layer (n-
AlGaInP cladding layer) 31, MQ having a thickness of 50 nm
W active layer 32, p-type AlGaIn having a thickness of 0.25 μm
A first cladding layer (p-AlGaInP first cladding layer) 33 made of P, a 1.5 μm-thick p-type AlGaIn
After a second cladding layer (p-AlGaInP second cladding layer) 34 made of P is sequentially stacked and formed,
A ridge 35 is formed by removing both sides of the AlGaInP second cladding layer 34 by etching and leaving the p-AlGaInP second cladding layer 34 in a stripe shape. On the p-AlGaInP first cladding layer 33 on both sides of the p-AlGaInP second cladding layer 34, a block layer (n-GaAs) made of n-type GaAs is formed.
(s block layer) 36 is formed. In addition, the p-
Ridge 35 composed of AlGaInP second cladding layer 34
And a thickness of 3.0 on the n-GaAs block layer 36.
μm p-type GaAs cap layer (p-GaAs
(s cap layer) 37.

Although not shown, a cathode electrode is provided on the lower surface of the n-type GaAs substrate 30, and an anode electrode is provided on the p-GaAs cap layer 37.

The resonator, that is, the optical waveguide is made of n-GaAs.
The ridge 35 is formed between the block layers 36 and has a constant width over the entire length (C). The ridge 35 has a trapezoidal cross section. The length (a) of the upper side is, for example, about 2.0 μm, and the length (b) of the lower side is, for example, 5-6 μm.

On the other hand, this is one of the features of the present invention. The portion of the n-GaAs block layer 36 which overlaps the ridge 35 is partially protruded, and a narrow portion 40 for reducing the width of the current injection portion is provided. Have been. This narrow part 40
Are formed by partially projecting the n-GaAs block layer 36 on both sides of the ridge 35. That is,
Since the n-GaAs block layer 36 is formed on both sides of the ridge 35 formed by the p-AlGaInP second cladding layer 34, current is injected into the p-GaAs cap layer 37 between the pair of n-GaAs block layers 36. Become a department.
Therefore, the projecting portion of the pair of n-GaAs block layers 36 is formed on the p-GaAs cap layer 37 on the ridge 35.
Is narrowed, and the current injection portion is narrowed. The width (W) of the narrow portion 40 is, for example, 0.5 to 1.0 μm. Also, n-GaAs for forming the narrow portion 40
The overhang (overhang portion 41) of the s block layer 36 is the same in the n-GaAs block layers 36 on both sides of the ridge 35.

As shown in FIG. 1, this narrow portion 40
They are provided over a length (C2, C4) inside a predetermined distance (C1, C5) from the end of the resonator. The two narrow portions 40 provided in this manner are separated by a distance (C3).

In the first embodiment, the narrow portion 40 is provided corresponding to the resonator portion where the swell width of the swell of the swell generated in the resonator becomes a maximum value. The length of the resonator portion where the width of the undulation of the undulating standing wave is at a maximum value is at least 40 μm in order to suppress the occurrence of kink.
Degree is necessary. Although not shown, coatings are provided on both end faces of the semiconductor laser device 1a, that is, on the end faces of the resonator, for the purpose of preventing oxidation of the end face of the resonator (optical waveguide) and controlling the reflectance. The coating comprises an AR film (low reflectance film) having a low reflectance provided on the front emission surface, and an HR film (high reflectance film) having a high reflectance provided on the rear emission surface.

For writing on an optical disk, an optical output of 30 m
A high power laser diode of W or more is used. In a high-power laser diode, it is necessary to increase the width of the light-emitting portion in order to secure the light output. Therefore, the structure is such that the primary mode in the horizontal direction (light distribution is two peaks) is not cut off.

Particularly in the case of a ridge structure, the side of the ridge is G
Those buried with aAs oscillate in the zero-order mode because the loss in the higher-order mode is large. However, first-order modes can also propagate. The 0th-order and 1st-order modes have different propagation constants, that is, different speeds in the direction of the resonator. Normally, these are coupled, so that they travel in the optical waveguide while undulating in the horizontal direction.

Therefore, if the length of the resonator coincides with the pitch of these undulations, a undulating standing wave is generated,
The generation of the standing wave deteriorates the linearity of the current light output.

Since the difference in the propagation speed of the mode changes depending on the change in the refractive index due to the local temperature of the light emitting portion, the carrier concentration, and the like, it changes depending on the pulse width of the drive current, and the pitch of the undulation also changes depending on the drive conditions. Therefore, depending on the driving conditions,
If the pitch of the undulation coincides with the length of the laser cavity, the linearity of the current light output of the laser deteriorates, and a recording mark cannot be formed properly by constant current driving.

If the width of the light emitting portion is reduced until the primary mode is cut off, such a problem will not occur.
Light density and current density are increased, and high output cannot be obtained.

By narrowing only the current injection width at the portion where the swell width becomes the maximum value in the laser of the light source, the gain of the higher-order mode is reduced, the generation of the swell standing wave is suppressed, the kink is suppressed, and the high output is obtained. Can be As a result, even if the drive pulse width changes, it is possible to prevent the linearity of the current-light output characteristic from deteriorating, and to prevent the light output from fluctuating during constant current driving. In addition, in order to reduce writing failure with a laser having poor current-light output characteristic linearity, an additional circuit for correcting light output at high speed is required. -If the linearity of the light output characteristic is improved, the correction circuit becomes unnecessary, and the simplification and miniaturization of the circuit of the optical disk device can be achieved.

The semiconductor laser device 1a of the first embodiment is
For example, the semiconductor laser device 1b (semiconductor laser 1) is incorporated in a package as shown in FIG.

As shown in FIG. 4, the semiconductor laser device 1b includes a plate-like stem 50 which is a main component of the assembly, and a cap 51 which is hermetically fixed to the main surface of the stem 50. . The stem 50 is several meters
It is a circular metal plate having a thickness of m and a heat sink 52 made of copper is fixed to the center of the main surface (upper surface) with a brazing material or the like. The semiconductor laser device 1a is fixed to a side surface of the heat sink 52 via a submount 53. This semiconductor laser element 1a emits laser light 2 from the upper and lower ends thereof.

The submount 53 is made of SiC having good thermal conductivity. Although not shown, the semiconductor laser element 1a has an anode electrode surface of PbS
It is mounted on the submount 53 by being fixed on a metallization layer provided on the submount 53 via a bonding material made of n or the like. This structure is a p-down structure, and the distance to the MQW active layer serving as a heat source is short and the heat dissipation is high. Therefore, the laser operates stably.

On the other hand, a light receiving element 55 for receiving the laser light 2 emitted from the lower end of the semiconductor laser element 1a and monitoring the light output of the laser light 2 is fixed to the main surface of the stem 50. Further, three leads 56 are fixed to the stem 50. One lead 56 is a stem 5
The other two leads 56 penetrate the stem 50 and are electrically insulated and fixed to the stem 50 via an insulator 57 such as glass. ing. 2 projecting from the main surface of the stem 50
The upper ends of the leads 56 are connected to the respective electrodes of the semiconductor laser element 1 a and the light receiving element 55 via wires 60.

On the other hand, the main surface of the stem 50 is fixed to a metal cap 51 having a window 61 to seal the semiconductor laser element 1a and the heat sink 52. The window 61 is formed by hermetically closing a circular hole provided in the ceiling of the cap 51 with a transparent glass plate 62. Therefore, the laser beam 2 emitted from the upper end of the semiconductor laser device 1a is transmitted through the transparent glass plate 62 and emitted outside the package formed by the stem 50 and the cap 51. The stem 50 has a pair of V-shaped notches 6 provided on the outer periphery thereof so as to face each other.
5 and a rectangular notch 66 are provided for positioning during assembly.

The semiconductor laser device of this embodiment emits laser light 2 from the semiconductor laser element 1a by applying a predetermined voltage to a predetermined lead 56.

According to the first embodiment, the following effects can be obtained. (1) The semiconductor laser (semiconductor laser element 1a) that writes data on the disk 8 has a narrow portion 40 where the width of the current injection portion where the width of the undulation of the standing wave of the undulation in the resonator becomes a maximum is narrow. Due to the structure, in the narrow portion 40, the gain of the higher-order modes including the first-order mode decreases, and the generation of the standing wave with the undulation can be suppressed, and the generation of the kink can be suppressed. it can.
Therefore, when writing is performed on the disk 8, a writing error such as a reduction in the size of a recording mark or a displacement due to a shortage or delay of the optical output does not occur. (2) Since no kink is generated in the semiconductor laser element 1a, it is possible to prevent the linearity of the current-light output characteristic from deteriorating even when the drive pulse width changes, and to prevent the fluctuation of the light output during constant current driving. can do. Thereby, writing can be performed stably. (3) An additional circuit for correcting the optical output at high speed is necessary to reduce the writing failure with a laser having poor current-optical output characteristic linearity. -Since the linearity of the light output characteristic is improved, a correction circuit becomes unnecessary, and simplification and downsizing of the circuit of the optical disk device can be achieved.

Although the invention made by the present inventor has been specifically described based on the embodiments, the present invention is not limited to the above embodiments, and various modifications can be made without departing from the gist of the invention. Needless to say. For example, in the above embodiment, the semiconductor laser for writing has been described as an example of the ridge structure. However, other semiconductor lasers, that is, semiconductor lasers having a buried heterostructure or the like having an internal constriction type can be similarly applied. it can.

[0044]

The effects obtained by the representative ones of the inventions disclosed in the present application will be briefly described as follows. (1) In the optical disk device, the width of the current injection portion of the writing semiconductor laser is narrowed at a portion where the undulation width of the undulating standing wave has a maximum value (narrow structure). (1) The gain of high-order modes such as the first-order mode is reduced, and the generation of standing waves with undulations can be suppressed. Therefore, the occurrence of kinks at the time of high output at the time of writing can be suppressed, and the recording mark on the optical disk can be reduced. It is possible to prevent the occurrence of a writing error such as a shift and a displacement.

[Brief description of the drawings]

FIG. 1 is a partially cut-away schematic perspective view showing a semiconductor laser device incorporated in an optical pickup mechanism of an optical disk device according to an embodiment (Embodiment 1) of the present invention.

FIG. 2 is a schematic diagram illustrating an optical pickup portion of the optical disc device according to the first embodiment.

FIG. 3 is an explanatory diagram showing a mark edge recording method using laser light and a mark edge recording state in the optical disc device of the first embodiment.

FIG. 4 is a partially cutaway perspective view showing a semiconductor laser device incorporated in the optical disc device of the first embodiment.

FIG. 5 is an explanatory diagram showing a mark edge recording method using a laser beam and a mark edge recording state according to a conventional method.

FIG. 6 is an explanatory diagram showing a defective mark edge recording state caused by a kink.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Semiconductor laser, 1a ... Semiconductor laser element, 1b ... Semiconductor laser device, 2 ... Laser light, 3 ... Half mirror, 4
... Collimate lens, 5 ... Wavelength selection mirror, 6 ... Two lens actuator, 7 ... DVD objective lens, 8 ... Disk, 9 ... Photodetector, 15 ... Semiconductor laser, 16 ... Laser light, 17 ... Half mirror, 18 ... Collimating lens,
19: CD objective lens, 20: Photodetector, 21: Laser drive circuit, 22: Preamplifier circuit, 23: Demodulator, 2
4 ... APC circuit, 30 ... Semiconductor substrate (n-type GaAs substrate), 31 ... Cladding layer (n-AlGaInP cladding layer), 32 ... MQW active layer, 33 ... First cladding layer (p
-AlGaInP first cladding layer), 34 ... second cladding layer (p-AlGaInP second cladding layer), 35 ... ridge, 36 ... block layer (n-GaAs block layer),
37 ... cap layer (p-GaAs cap layer), 40 ...
Narrow part, 41 ... overhang, 50 ... stem, 51 ... cap, 52 ... heat sink, 53 ... submount, 55 ...
Light receiving element, 56 lead, 57 insulator, 60 wire, 61 window, 62 glass plate, 65 V-shaped notch,
66 ... rectangular notch.

Claims (7)

[Claims] 1. An optical disk device having a semiconductor laser as a light source and an optical pickup mechanism for connecting a spot light for an optical pickup to an optical disk surface by an optical system, wherein the semiconductor laser has a current injection portion having a width different from that of another portion. An optical disk device having at least one or more narrower portions. 2. The portion where the width of the current injection portion is narrow has a maximum value of the amplitude of the standing wave of the swell generated by the difference between the horizontal 0th order and the 1st order propagation constant propagating through the resonator. The optical disk device according to claim 1, wherein the optical disk device is located at a position. 3. The part where the width of the current injection part is narrow is 4c in the horizontal primary mode and the zero-order mode of the emitted laser light.
3. The optical disk device according to claim 1, wherein the width is such that a gain difference of at least m ^-1 occurs. 4. The optical disk device according to claim 1, wherein said semiconductor laser forms a high-output semiconductor laser capable of writing on an optical disk surface. 5. The optical disk device according to claim 1, wherein the semiconductor laser is a semiconductor laser having a cavity having a ridge structure, a buried heterostructure, or the like and an internal confinement type. . 6. The optical disk device according to claim 1, wherein the width of the resonator is constant. 7. The semiconductor laser is incorporated in a package comprising a package body and a lid having a light transmission window for transmitting laser light, and each electrode of the semiconductor laser is attached to the package body. 7. The package according to claim 1, wherein the package is electrically connected to a plurality of external electrode terminals extending inside and outside the package via connection means. An optical disk device according to the above.